A protective net is formed of individual loops (12, 12', 12") of plastics material threaded into each other. The plastics material can have a modulus of elasticity of between approximately 5000 and approximately 20000 MPa. Each loop (12, 12', 12") of the protective net (10) can be formed by a thread (14) of plastics material wrapped repeatedly over itself. The protective net (10) can be used in an aquaculture installation for the purpose of anti-breach protection for a cage for breeding aquatic organisms.